Cosmetic use of an extract of balanites almonds to improve hair strength

ABSTRACT

The invention concerns the use of a cosmetic compound to improve hair strength, said cosmetic compound comprising as an active ingredient an extract of Balanites almonds.

This invention relates in general to compositions for hair and more specifically compositions intended to improve hair strength with an anti-breakage action.

The field of the present invention relates to a new method for upgrading an almond extract of a plant belonging to the Balanites genus of the Zygophyllaceae family. Preferentially, this invention relates to the work conducted on the Balanites aegyptiaca L. Delile species because of it is easy to procure in Africa. However, this feature is non-limiting and an extract of comparable quality with other species of the Balanites genus coming from other countries may also be envisaged. It is possible to cite, for example: Balanites triflora Tiegh and Balanites roxburgghii Planch.

Balanites aegyptiaca is also more commonly called desert date.

Balanites is a tropical Afro-Asian genus, with around 25 species, of dry sub-arid regions with mean annual rainfall of between 1000 mm and 200 mm and even 100 mm. Its geographic area of distribution extends from Africa, in the West (Senegal-Mauritania coasts), to Myanmar, in the East. Balanites aegyptiaca is present in dry tropical Africa, from Senegal to Sudan, Oriental Africa, from Egypt to Zambia, Arabia and India. It arrived in Asia from the Mediterranean via Egypt. It is one of the most common trees in Senegal.

The desert date is a flat or irregular decurrent crown tree reaching 8 to 9 m in height. It is highly remarkable with its soft falling branches with long alternate or more or less spiral spines.

Its fruit is an ellipsoid drupe of 5×2.5 cm, green and pubescent, turning yellow and more or less glabrous at maturity. A thin skin envelops an edible pulp (which represent 43% of the weight of the fresh fruit) around a hard, ovoid and sharp core, containing the almond.

The high carbohydrate and vitamin content of the fruit justifies its name “desert date”. It is well liked by children and adults.

All of the portions of the tree are used in traditional African pharmacopeia.

-   Roots: Snakebite, anthrax -   Bark: Jaundice, yellow fever, syphilis, cough, epilepsy and anxiety -   Spines: Leprosy -   Leaves: Asthenia, anthrax -   Fruits: Rheumatism, gentle laxative -   Seeds: Oil used in the form of a pomade and an ointment with     numerous drugs.

The almond oil is used as a fat for artisanal soap production.

The prior art in the cosmetic field relates primarily to Balanites oil (mention may be made of EP 0 781 545—concerning the hydration of the upper layers of the skin).

Surprisingly and unexpectedly, the applicant has identified an original activity of a Balanites almond extract, concerning its anti-breakage properties for hair. This type of activity is especially beneficial for improving hair strength and more specifically for dry, damaged and breaking hair.

Below, the content of the compounds of the extract will be indicated for the extract without any drying medium.

The Balanites almond extract according to this invention is characterized in that it comprises wax, amino acids, proteins and total sugars.

In the sense of this invention, “wax” refers to fatty alcohol esters; and “total sugars” refers to the sugar content after hydrolysis of the extract.

Qualitatively, the extract according to this invention differs significantly from oil. In fact, even though certain fatty acids and hydrocarbons are also present in our extract as in oil, waxes, free amino acids, proteins and sugars are absent from the oil. These are the technical features retained in order to differentiate our extract from a Balanites oil already used in cosmetics.

The extract used in the context of this invention can be prepared as follows.

The almonds of the desert date seed are preferably extracted by a mixture of water and one or more organic solvents.

The organic solvent can be an alcohol (methanol, ethanol, propanol, isopropanol, butanol, octanol), a ketone (methylethyketone, methylisobutylketone), as well as mixtures thereof.

The extract without a drying medium is obtained with a yield of around 25%. This extract is heterogeneous, consisting of a liquid fatty phase (upper phase, 65%) and a solid phase with a buttery aspect (lower phase, 35%). The addition of an inert medium (such as maltodextrin) can enable a homogeneous extract to be obtained.

The extract can also be stabilized by adding an antioxidant such as, for example, butylhydroxytoluene or alpha tocopherol in amounts of between 0.05 to 1 g % of dry extract.

Characterization of the extract (content expressed as g/100 g of extract without a drying medium):

-   -   waxes: from 1% to 10% and preferably 4%     -   free amino acids: 1% to 5% and preferably 2%     -   proteins: from 0.5% to 10% and preferably 1 to 5%     -   total sugars: from 20% to 60% and preferably 28%.

This invention relates to the use of a cosmetic composition for improving hair strength, said cosmetic composition including, as an active principle, a Balanites almond extract as described above.

This Balanites extract is moreover, in consideration of its chemical composition high in sugar, amino acids and proteins, waxes and fatty acids, particularly nutritious for hair.

The Balanites almond extract according to this invention makes it possible to nourish the hair fibre by providing it with elements essential for strength and nutrition, and makes the treated hair more resistant to breakage.

Preferably, the hair being treated is fragile, dry, damaged and breaking.

A significant increase in the breakage stress point has been observed in hair treated with an extract according to the invention.

This invention finally relates to a method for cosmetic treatment of hair intended to improve hair strength with an anti-breakage effect consisting in applying, to the hair, a cosmetic composition containing a Balanites almond extract according to the invention.

Preferably, the amount of Balanites almond extract is between 0.05 and 5% with respect to the total weight of the composition and, preferably, said amount of extract is between 0.05 and 1% with respect to the total weight of the composition.

The cosmetic composition according to the invention may advantageously be in any galenic form normally used in the cosmetic hair care field for topical use. Preferentially, the topical form may in particular be in the form of a shampoo, a balm, a mask, a gel, a lotion, a foam, a spray or a cream.

Thus products designed to be rinsed out are distinguished from those not designed to be rinsed out.

The cosmetic composition according to the invention also includes conventional cosmetically compatible carriers.

The conventional carriers compatible with the cosmetic hair composition may be any carrier among those known to a person skilled in the art for obtaining a cosmetic composition for topical use in the forms as described above.

The cosmetic composition according to the invention may in particular contain formulation additives and aids, such as surfactants of the emulsifying, cleaning, foaming type, etc., complexing agents, thickening agents, gelling agents, stabilizers, preservatives including antimicrobial agents and antioxidants, conditioners, acidifiers, alkalinizers, softeners, solvents, colouring agents, and fragrances.

The following examples are provided as a non-limiting indication.

Example 1 of Preparation of Plant Extract According to the Invention

1 kg of Balanites almonds are extracted with 10 litres of alcohol with 80% (v/v) reflux for 1 hour under agitation.

After filtration and rinsing of the pomace, the filtrate is concentrated, then dried on 750 g of maltodextrin, then stabilized by adding 0.2% alpha-tocopherol.

The extract is a yellowish powder obtained with a yield of around 100% (p/p).

The extract contains (value expressed without drying medium): 4% wax, 2.1% free amino acids, 1.1 to 5% proteins and 28% total sugars.

Example 2

1 kg of Balanites almonds are extracted with 10 litres of alcohol (v/v) at room temperature for 2 hours under agitation. After filtration and rinsing of the pomace, the filtrate is concentrated to up to 2 litres (concentrate 1) and stabilized by adding butylhydroxytoluene (BHT).

The alcohol-depleted pomace is extracted with 10 litres of EtOH 80% (v/v). After filtration and rinsing of the pomace, the filtrate is concentrated to up to 2 litres (concentrate 2).

0.8 litre of concentrate 2 is mixed with 0.2 litre of concentrate 1. After adding 750 g of maltodextrin, it is all dried in the Rotavapor.

The extract has a composition similar to that of the extract of example 1.

Examples of Cosmetic Compositions:

Example 3: Balm to be Rinsed Out

Balanites almond extract  0.1% Guar hydroxypropyltrimonium chloride  0.3% Propylene glycol  0.5% Sclerotium gum  0.3% Cetearyl alcohol/cetearyl mixture    2% Inulin lauryl carbamate 0.25% Cetyl alcohol    7% Ethylhexyl palmitate    8% Dicaprylyl carbonate    2% Hydrolyzed wheat protein    2% Sorbic acid  0.3% Salicylic acid 0.15% Phenoxyethanol  0.7% Colouring agents qsf Fragrance qsf Sodium hydroxide qsf Purified water qsf

Example 4: Shampoo

Balanites almond extract 0.1% Hydrolyzed wheat protein 0.5% PEG-7 glycerol cocoate   8% Ethoxylated olive oil   3% (Poly)quaternium-10 0.5% Decyl glucoside   2% Na lauroyl methyl isethionate   2% Sodium laureth sulfate  13% Lauryl betaine   5% Sodium benzoate 0.4% (Di)sodium EDTA 0.2% Colouring agents 0.1% Pearlescent base   8% Fragrance qsf Citric acid monohydrate qsf Sodium chloride desulfate qsf Purified water qsf

Example 5: Mask

Hydrolyzed wheat protein    3% Balanites almond extract  0.2% Salicylic acid 0.15% Guar hydroxypropyltrimonium chloride  0.5% Propylene glycol   1% Behentrimonium chloride    3% Cetearyl alcohol/cetearyl mixture    1% Inulin lauryl carbamate 0.15% Glycol palmitate    6% Behenic alcohol    4% Diisopropyl adipate   10% Castor oil    3% Phenoxyethanol  0.7% Sorbic acid  0.3% Fragrance qsf Lactic acid qsf Butylhydroxytoluene 0.05% Colouring agents qsf Purified water qsf

Example 6: Skincare Without Rinsing

Balanites almond extract  0.1% Hydrolyzed wheat protein  0.1% (Poly)acrylate-13 mixture  1.5% (Di)caprylyl ether    5% Castor oil    5% C14-22 alkyl alcohol mixture 1.25% Guar hydroxypropyltrimonium chloride  0.3% Propylene glycol    1% Phenoxyethanol  0.5% Sorbic acid  0.2% Butylhydroxytoluene 0.01% Fragrance qsf Colouring agent qsf Purified water qsf

Example 7: Measurements of Mechanical Properties of the hair treated with a Balanites aegyptiaca almond extract.

The mechanical properties of the hair are measured by means of a linear extensometer that applies a tensile force until the hair breaks. Thus, by means of a force sensor, the breakage force can be measured. By taking into account the cross-section of the hair, the breakage force is associated with the cross-section and expressed as the breakage stress point.

Method

Hair Used

Original hair: European type, brown, glued weft dense, colour 5/0, total length 20 cm with 18 cm free. Provided by the Kerling International company (Germany).

And hair made fragile obtained by chemical treatments of the original hair: discoloured by chemical oxidation for 4 hours followed by a 30-minute permanent treatment.

The lock of hair made fragile was cut into a plurality of sub-locks with a width of 0.5 cm (mean weight=270±30 mg). Then, these sub-locks were the subject of the test in an amount of one product tested per sub-lock.

Products Tested

The preparations tested were obtained by using, respectively, 5 g and 0.5 g of extract prepared according to example 1 in suspension in 27% ethanol.

-   -   100 mL of 5% date extract in 27% ethanol     -   100 mL of 0.5% date extract in 27% ethanol     -   100 mL of 27% ethanol.     -   Application of the Products

The hair made fragile was treated with the preparations, allowing the locks to soak for 96 hours in the solutions, and agitating them during this time.

The untreated hair made fragile locks were used as a control.

At the end of the treatment, the hair locks were washed for 30 seconds with 3% sodium lauryl sulfate, followed by rinsing in clear water for 1 minute.

Finally, the locks were dried for 24 hours in open air before being subjected to the tests according to the protocol below.

Measurement of Mechanical Properties

The equipment used is a Miniature Tensile Tester 675 (MTT, Diastron, UK) associated with a Laser Scan Micrometer (LSM, Mitutoyu, Japan). The procedure for measurement and analysis of the hair is as follows:

-   -   Crimping the individual hair strands with a test length of 30 mm         (n=40 hair strands per treatment)     -   Measuring the cross-section of each hair strand by LSM     -   Subjecting wetted hair strands (1 hour of soaking in water) to         tensile stress until breakage by the MTT. Constant pull rate=10         mm/mn     -   Analysis of the tensile curve in order to identify and raise the         breakage stress point in megapascal (MPa, where 1 Pa=1 N/m²),         which indicates the breakage force weighted by the cross-section         of the hair strand. The variability in the thickness of the hair         studied is thus overcome.

This procedure was used to measure and analyse locks having been treated and also locks not having received any treatment (untreated controls).

Results (n=40 Hair Strands Per Treatment)

The results of the measurements of the breakage stress point are presented in table 1, with mean values for the breakage stress points and corresponding standard deviations. The differences with respect to the untreated control were calculated in the form of percentages.

TABLE 1 Breakage stress point in MPa for hair tested as a function of treatment Mean breakage stress point Standard Treatment (MPa) deviation % Untreated 51.56 11.46 0.0 control 0.5% date 55.97 7.59 8.5 5% date 57.67 10.00 11.8

A statistical analysis (Student T test, unpaired, bilateral) of these results was performed with the Student test (threshold 5%)

-   -   Treated with 0.5% Balanites extract, p=0.0468 (Significant)     -   Treated with 5% Balanites extract, p=0.0131 (Significant)

CONCLUSIONS

Under these experimental conditions, a significant increase in the breakage stress point is observed for the two concentrations of date extracts with respect to the untreated control.

These results indicate a reinforcing effect of the active agent on hair made fragile. Thus, the latter, when they were treated by the extract and subjected to a constant pull rate, break with greater force than that of the untreated hair.

This study made it possible to demonstrate the efficacy of a composition according to this invention on the anti-breakage property of hair. 

1. Use of a cosmetic composition for improving hair strength, said cosmetic composition including, as an active principle, a Balanites almond extract.
 2. Use according to claim 1, characterized in that the Balanites almond extract includes the following contents expressed as percentages by weight with respect to the extract without a drying medium: waxes: from 1% to 10% and preferably 4% free amino acids: 1% to 5% and preferably 2% proteins: from 0.5% to 10% and preferably 1 to 5% total sugars: from 20% to 60% and preferably 28%.
 3. Use according to any one of the previous claims, characterized in that the amount of extract is between 0.05 and 5% by weight with respect to the total weight of the composition.
 4. Use according to one of claims 1 to 3, characterized in that said extract is a Balanites aegyptiaca, Balanites triflora Tiegh or Balanites roxburgghii Planch extract, and preferably Balanites aegyptiaca.
 5. Method for cosmetic treatment of the hair intended to improve hair strength with an anti-breakage effect consisting in applying, to the hair, a cosmetic composition according to claims 1 to
 4. 6. Cosmetic composition containing, as an active principle, a Balanites almond extract having the following contents expressed as percentages by weight with respect to the extract without a drying medium: waxes: from 1% to 10% and preferably 4% free amino acids: 1% to 5% and preferably 2% proteins: from 0.5% to 10% and preferably 1 to 5% total sugars: from 20% to 60% and preferably 28%. 